I am hoping some of the more knowledgeable posters here can help me find some plants that will work for my front porch.

I have two cast iron urns on each side of my front door. The area is totally covered by the balcony above, and remains fully shaded. I need to get to plants for these urns, of medium height (as in not ground-hugging flowers and the like).

Topiaries would be the ideal style I am going for, but the lady helping me at the plant nursery said they would not work in full shade. The only plant she could suggest was a tall fern. Ferns are really too loose and informal a look than I am trying to achieve.

Does anyone have any other suggestions? Any help is greatly appreciated!